IMHO Madrid will drop points in 2 different games of the 9 remaining. Coming up, they will drop points in either Sevilla-away, Rayo-home, or Sociedad-away. Sevilla and Sociedad will be particularly difficult. Both Sevilla and Sociedad are competing for Europe and Sanchez-Pisjuan and Anoeta are tough stadiums to play.
Then IMO, they will also drop points towards the end in either Valencia-home or Celta-away. Valencia are a good team that is under-achieving, and Celta played Madrid really well at the Bernabeu.
It will be tight, with very little room for error, but if Barcelona can get their shit together and win out, I think Madrid will not go undefeated the remaining 9 games.
Altetico might be a more worrisome entity though.